Performance improvement in tensor allocation

- Tensor allocation verification was O(N^2), is now closer to O(N)
- Removed a sort in HillClimb allocator

Change-Id: I286a269881490c485cc2b0eeab3b1ecffa8f3df0
Signed-off-by: Louis Verhaard <louis.verhaard@arm.com>
diff --git a/ethosu/vela/test/test_tensor_allocation.py b/ethosu/vela/test/test_tensor_allocation.py
new file mode 100644
index 0000000..f437bbb
--- /dev/null
+++ b/ethosu/vela/test/test_tensor_allocation.py
@@ -0,0 +1,46 @@
+# Copyright (C) 2021 Arm Limited or its affiliates. All rights reserved.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+# Licensed under the Apache License, Version 2.0 (the License); you may
+# not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an AS IS BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# Description:
+# Contains unit tests for tensor allocation
+import pytest
+
+from ethosu.vela.data_type import DataType
+from ethosu.vela.errors import AllocationError
+from ethosu.vela.live_range import LiveRangeGraph
+from ethosu.vela.tensor import Tensor
+from ethosu.vela.tensor_allocation import verify_allocation
+
+
+def test_verify_allocation():
+    # Create live range graph with 2 live ranges with overlapping start/end time
+    lr_graph = LiveRangeGraph()
+    t1 = Tensor([1, 100, 10, 10], DataType.int8, "t1")
+    lr1 = lr_graph.get_or_create_range(t1)
+    lr1.mark_usage(4)
+    lr1.mark_usage(8)
+    t2 = Tensor([1, 10, 20, 10], DataType.int8, "t2")
+    lr2 = lr_graph.get_or_create_range(t2)
+    # Set overlapping addresses, should lead to verification failure
+    lr1.set_address(16)
+    lr2.set_address(32)
+    lr2.mark_usage(7)
+    lr2.mark_usage(12)
+    with pytest.raises(AllocationError):
+        verify_allocation(lr_graph, 16)
+    # Set non-overlapping addresses, verification should now succeed
+    lr2.set_address(None)
+    lr2.set_address(160000)
+    verify_allocation(lr_graph, 16)